1. Field of the Invention
This invention pertains to a normally open vented parachute having a control center and structure for incrementally closing the vent, to a propulsive parachute for a work load such as a snow skier who wants to go uphill, to a method of controlling a normally open and vented parachute, and to a method of propelling a work load such as a skier, with a parachute device.
2. The Prior Art
The use of a parachute device for propulsion of a work load is known and has been done before.
U.S. Pat. No. 4,127,247 by Dieter Strasilla of Germany is the most pertinent known prior effort at a device of this type. Strasilla has a parachute which is connected to a skier by his invention of a quick release lock, and control lines to sides of the chute are provided for directional control.
The use of controlled vents in parachute devices is also known and has been done before.
S. Nonala U.S. Pat. No. 2,116,037 has a normally closed apex vent which can be selectively in incrementally open with a control line to increase the rate of decent.
L. J. Davies U.S. Pat. No. 3,193,222 has a normally closed apex vent with wedge shaped apex panels. Upon excessive load of the canopy, the vent breaks open when a fuse tie breaks. This device is a single usage structure and the vent cannot be reclosed while in operation.
W. E. Tingle U.S. Pat. No. 2,127,895 has a normally closed apex vent that can be selectively opened with a center pull control line for increasing the rate of decent.
R. Karpf U.S. Pat. No. 3,152,782 and A. A. Barton U.S. Pat. No. 1,477,163 are more or less functionally equivalent to Tingle, with a different vent valve structure.
Other known prior art of lesser pertinence consist of:
A. D. Centofanti: U.S. Pat. No. 3,806,070 PA1 E. D. Vickerey: U.S. Pat. No. 3,498,566 PA1 C. Rohulick: U.S. Pat. No. 2,404,659 PA1 R. V. Pence: U.S. Pat. No. 2,399,379
All of the known prior endeavors utilize a normally full parachute and the control, if any, is for opening the vent and decreasing output of the canopy.
If and when these devices are used as propulsive units, they have no safety provisions, for deflation in the event of an emergency, other than to completely release the canopy as is one by Strasilla.
There are no structures for gently increasing the output of the canopy. For example, upon initial inflation of Strasilla's canopy you have 100% output. You cannot decrease the output to ease the shock or to slow down. You go wide open or not at all. To stop you have to release the canopy. If the suspension lines become fouled on your body or equipment, you cannot even release the canopy.
When skiing, there are such things as cliffs, trees, rocks, crevasses, stuck skiers, falls and the like that have to be expected and confronted with technique.
Strasilla has no structure or method for solving these adversities of travel with a parachute propulsive device. Further, a person wants to have a gentle start, be able to speed up and/or slow down, keep pace with a companion, stop either gently or immediately and, in general, be in complete control of self destiny. A person also wants to be able to utilize the device in varying winds, be they high, low, or gusty. While Strasilla may be suitable for crossing an un-obstructed frozen lake, his structure is essentially unusable on hills or mountains or in obstructed topography.